Buckling column bumper system with vertical displacement-preventing means

ABSTRACT

A horizontal bumper is supported in relation to a support such as a vehicle frame directly by means of resilient buckling column bars for impact energy storing during displacement of the bumper relative to the frame as permitted by the bars, whereafter the bars return the bumper system to normal position. Jacking and anti-roll support for the bars, as well as stress limiting means, and frictional energy absorption are provided.

United States Patent [191 McLauchlan BUCKLING COLUMN BUMPER SYSTEM WITHVERTICAL DISPLACEMENT-PREVENTING MEANS [75] Inventor: John McLauchlan,Royal Oalr, Mich.

[73] Assignee: IIoudaille Industries, Inc., Buffalo,

[22] Filed: Apr. 30, 1971 [21] Appl. No.: 138,879

[52] US. Cl 293/70, 293/89, 293/99 [51] Int. Cl. B60! 19/06 [58] Fieldof Search 293/60, 69, 70, 80,

[56] References Cited UNITED STATES PATENTS 3,l72,268 3/1965 Gensheimer61/48 [111 3,73,696 June 12, 1973 1,531,508 3/1925 Roth 293/84 1,825,0869/1931 Ohlendorf.. 293/85 3,433,520 3/1969 Kearns et al 293/85 PrimaryExaminer-Gerald M. Forlenza Assistant Examiner-Robert SaiferAttorney-Hill, Sherman, Meroni, Gross & Simpson 57 ABSTRACT A horizontalbumper is supported in relation to a support such as a vehicle framedirectly by means of resilient buckling column bars for impact energystoring during displacement of the bumper relative to the frame aspermitted by the bars, whereafter the bars return the bumper system tonormal position. Jacking and anti-roll support for the bars, as well asstress limiting means, and frictional energy absorption are provided.

22 Claims, 13 Drawing Figures mam PAIENTED JUN i 2 mmam JOHN McLAUCHLANM W Affys l BUCKLING COLUMN BUMPER SYSTEM WITH VERTICALDISPLACEMENT-PREVENTING MEANS This invention relates generally to energystoring bumper support systems utilizing resilient buckling column bars,and is more particularly concerned with the mounting of automobilebumpers in a manner to protect the same and the adjacent structure ofthe vehicle against damage from at least minor collisions to which suchbumpers may be subject in the operation of the associated vehicles.

Any moving object developes a certain kinetic energy level proportionalto its speed or velocity squared. When the moving object impacts againstanother moving object or a non-moving object, this kinetic energy mustbe dissipated and this may occur by deformation of structure or by beingstored or absorbed, for example, in a bumper system.

Relating the foregoing specifically to automotive vehicles, and moreparticularly to automobiles, excessive damage to not only the bumpersbut also the adjacent portions of the vehicles has been experienced inrespect to present-day bumper designs which have, to a large extent,become mainly decorative trim for the vehicles. Further, it is generallyknown that in the automobile industry designers are extremely reluctantto sacrifice any styling potentialities, so that there has been a widedraft away from and a virtual impossibility to return to the ruggedspring bumpers of an earlier day when the bumpers themselves weregenerally constructed to absorb rather significant impacts withoutdamage either to the bumpers or to the associated vehicle structure. Forreasons of expediency bumpers are generally constructed as shells ofrelatively soft steel virtually lacking in spring characteristics andunduly liable to be dented and cracked under rather low impact, and moreparticularly impacts occurring at low as 3 miles per hour up to aboutmiles per hour of one vehicle relative to another, where the bumpers aremounted in an essentially fixed or rigid manner relative to the vehicleframe. To alleviate this serious liability to damage with insuranceclaims mounting to exorbitant proportions, various expedients haveheretofore been proposed, such as constructing the bumpers offluid-filled resilient tubes, or equipping them with rubber cushions,but such expedients have been largely resisted by the automobileindustry and the purchasing public due to detraction from designerlatitude, cost, unattractive appearance, and the like. Coiled springs orrubber cushions behind the bumpers have been proposed, but these havebeen unsatisfactory because they introduce an undesirable springperformance characteristic into the system which is representable by achart curve showing unduly soft resistance at the beginning of impact,thus requiring excessive travel distance to be effective. A furtherproposal has been to provide collapsibly yieldable structure in thebumper system, but that requires replacement of the system or parts ofthe system or a physical resetting after impact. Although hydraulicbuffers or dampers are highly efficient and'may be used in such system,they are not as versatile as desirable in respect to the direction ofimpact force, and they add unreasonable cost to original equipment,especially in medium and low priced automobiles, and automobilepurchasers resist the expenditure where offered as optional equipment.

Meanwhile, collision insurance rates have necessarily escalated becauseof the rising volume and size of damage claims, a significant proportionof which result from relatively minor car-to-car collisions whererelative vehicle movement is no more than from about three to ten milesper hour, such as in parking lot maneuvering, start-up situations, andcongested traffic incidents. This situation has become so serious thatnot only has there been an indication by the insurance industry of awillingness to reduce collision premium rates by as much as 20 percenton automobiles which can withstand at least a 3 mile per hour rear endbumper impact and 5 miles per hour front end bumper impact withoutdamage, but also Governmental standards have been or are beingimplemented to this end.

It is to the attainment of the desirable objective of meeting theproblems just outlined and to overcoming the deficiencies, defects,inefficiencies, shortcomings and undesirable factors in priorarrangements and proposals that the present invention is directed.

An important object of the present invention is to provide a new andimproved energy storing bumper support system which will meet at leastthe minimum requirements for absorption of impact or collision forceswithout damage to bumpers or adjacent portions of the vehicle.

Another object of the invention is to provide a new and improved energystoring bumper support system which can be produced and installed at lowcost.

A further object of the invention is to provide a new and improvedenergy storing bumper support system adapted to be installed withoutextensive modification of bumper or vehicle structure from currentdesigns and permitting wide latitude in designers options.

Still another object of the invention is to provide a new and improvedenergy storing bumper support system wherein the entire connectionbetween a bumper and a vehicle frame is provided by resilient bucklingcolumn bars, with novel jacking and roll prevention support for thebafs'.

Yet another object of the invention is to provide a new and improvedenergy storing bumper support system including resilient buckling columnbars and combined frictional energy absorbing means.

A yet further object of the invention is to provide a new and improvedresilient buckling column energy storing bumper support system includingnovel stress limiting means.

Other objects, features and advantages of the invention will be readilyapparent from the following description of certain preferred embodimentsthereof, taken in conjunction with the accompanying drawings, althoughvariations and modifications may be effected without departing from thespirit and scope of the novel concepts inherent in the disclosure, andin which:

FIG. I is a fragmentary plan view of a representative bumper systemembodying features of the invention;

FIG. 2 is a sectional elevational view taken substantially in the planeof line II-II of FIG. 1;

FIG. 3 is an enlarged fragmentary sectional detail view takensubstantially along the line III-III of FIG. 2;

FIG. 4 is an enlarged fragmentary sectional detail view takensubstantially along the line IV-IV of FIG.

FIG. 5 is a fragmental sectional elevational view taken substantiallyalong the line V-V of FIG. 1;

FIG. 6 is a fragmental sectional elevational view taken substantiallyalong the line VI-VI of FIG.

FIG. 7 is a sectional detail view taken substantially along the lineVIIVII of FIG. 6;

FIG. 8 is an elevational view taken substantially in the plane of lineVIIIVIII of FIG. 6;

FIG. 9 is a fragmentary plan view of a modified arrangement;

FIG. 10 is a sectional elevational view taken substantially along theline X-X of FIG. 9;

FIG. 11 is an enlarged fragmentary elevational view taken substantiallyin the plane of line XIXI of FIG.

FIG. 12 is a sectional detail view taken along the line XII-XII of FIG.11; and,

FIG. 13 is a fragmental plan view of a further modification.

A desirable feature of the present invention resides in that ahorizontal bumper 15 such as an automobile bumber is connected to andcarried on a support such as a vehicle frame 18 by resilient bucklingcolumn bars 18 and 19. The bumper 15 may be of any desired configurationand may be made from a desired suitable material, and, as shown,comprises a metal shell with reinforcing bar means 20 secured to itsinboard side and to which the buckling column bars are anchored. Thevehicle frame 17 desirably comprises a pair of longitudinal laterallyspaced frame rail or beam members 21, only one of which is showntogether with its associated bumper supporting system structure forconservation of drawing space since the opposite side is identical inreverse relative to the side shown. Transverse tie bar structure 22 isdesirable provided between enlarged outboard end portions 23 of the sideframe members.

In the arrangement shown, the buckling column bar means 18 extend in thesame longitudinal direction as the associated frame member 21 andconnect to the bumper 15 in general alignment therewith, while thebuckling column bar means 19 extend generally diagonally from the outerside of the frame member portion 23 toward and into connection with theadjacent end portion of the bumper 15 which extends sidewardlysubstantially beyond the line of longitudinal axis of the frame member21. Although for relatively smaller compact vehicle installations, thebuckling column bar means 18 and 19 may comprise single bars, in theillustrated instance heavier duty requirements are met by having the barmeans in the form of a plurality, herein shown as three, like barsassembled in laminar coextensive relation and operatively connected tothe bumper and frame in a manner which will attain mutual stable,efficient energy storing buckling as indicated in dash outline in FIG. 1in response to impact against the bumper forcing it to displace towardthe frame. Attachment of the outboard end of the buckling columnassembly 19 to the bumper 15 is by means of a bolt 24 secured fixedly tothe bumper reinforcement 20 and extending through a free clearance hole25 in a turned bearing pad terminal portion 27 of the bar assembly tofacilitate buckling bending deflections of the bar assembly, with rubbercushioning and take-up, anti-rattle pad means 28 between the head or nutof the bolt and the bar. At their inboard ends, the bars 19 are attachedas by means of a bolt 29 rigidly anchored to the side of the framemember portion 23 in this instance through an anchor plate 30 rigidlysecured to the frame as by means of bolts 31 and enabling attachment ofthe bars 19 at a higher elevation than otherwise. To facilitate rockingbearing movement of turned-inboard terminal 32 of the column assembly 19of the anchor bar 30, the bolt 29 extends through clearance hole 33 inthis terminal, and take-up, cushioning, rattle preventing block 34between the head or nut end of the bolt and the termi nal 32 yieldablypresses against the terminal.

Mounting of the buckling column bar means 18 is such that resilientbuckling deflectional movement of this bar means is adapted to be overthe frame member portion 23. To this end, abutment means in the form ofa thrust block bracket 35 (FIG. 1, 2, 5 and 6) is rigidly carried on theupper side of the frame member 21, in this instance spaced rearwardlysubstantially relative to the mounting of the inboard end of thebuckling column assembly 19 and against which the inner end of thebuckling column 18 is in thrusting bearing relation. In this instancethe abutment bracket 35 is provided with a recess 37 opening in theoutboard direction and accommodating the inboard end of the bar assembly18, with a cushioning take-up block 38 compressing the end portion ofthe bar assembly 18 toward the side of the recess 37 which is nearestthe inner side of the frame member 21, and with a retaining bolt 39extending through a clearance hole 40 in the bar terminal portion.

From the abutment 35, the bar assembly 18 extends in the outboarddirection to connection with the bumper 15 and more particularly thereinforcement 20 and to which the outboard end of the assembly isanchored by means of a bolt 41 providing a pivot on a vertical axisextending through a thrust knuckle 42 comprising a turned terminal endportion of one of the laminar bars of the assembly 18, with theremaining bars terminating short of the knuckle curl and with the barssecured together as by means of a rivet 43 in the outboard end portionswhile the remainder of the length of the bars remain in free laminarabutment facilitating relative sliding during resilient buckling. Tofacilitate mounting of the anchoring pivot pin 41, a generallyclevis-like or U-shaped bracket 44 is provided which is secured as bymeans of bolts 45 to the reinforcement 20 and provided with upper andlower coextensive horizontal, spaced inwardly direct flanges 47 betweenwhich the terminal knuckle curl 42 is received with the bolt 41therethrough and the bolt secured to the flanges 47.

In addition to its function as a buckling column bar supporting andoutboard abutment bearing for the curl terminal 42, the bracket 44provides means for energy absorption and means for buckling columnstress limitation. To this end, bracket 44 carries and has attached, bymeans of the bolts 45, to the inside of its base web flange, a baseflange 48 of a generally L-shape flange bracket extension including aradius portion 49 generally cradling the curl 42, and joining to theflange 48 a limited length longitudinally inwardly extending frictionpad flange 50 which freely faces the contiguous one of the bucklingcolumn bars 18. Engaged in frictional slidable relation with the outsideface of the flange 50 is a complementary combined friction pad andbumper position stabilizing and bottoming out buckling column stresslimiting flange 51 mounted in rigidly fixed relation on the outboard endof the frame portion 23 by means of a right angular base flange 52secured to the frame by means in this instance comprising bolts 53,although riveting or welding may be employed. Means for clamping thefriction pad flanges 50 and 51 in face-to-face frictional slidingengagement desirably comp-rise a bolt 54 having a pressure-applyingtake-up nut 55 and with the shank of the bolt anchored to the flange 50and extending through a longitudinal clearance slot 57 in the flange 51.Thereby on impact displacement of the bumper toward the supportingframe, the friction pad flange 50 will move inboard along the frictionpad flange 51 with energy absorbing effect, supplementing the energystoring action of the resilient buckling columns 18 and 19. Upon returnof the bumper by the outboard thrust imparted by the buckling columns asa result of the reaction from the energy stored therein, the frictionpad flanges 50 and 51 act again by energy absorption to damp rebound. Itwill be appreciated, of course, that the nut 55 of the bolt 54 must notbe tightened beyond effecting a clamping pressure at the interfacebetween the flanges and the inner face of the nut or washer companionthereto which will efficiently snub and attain smooth return of thebumper by the buckling columns and which will avoid locking the systemagainst such return.

In addition to the energy absorbing function just described, the flanges51 and 52 provide means to prevent vertical displacement of the bumperboth during jacking, that is lifting the associated vehicle by applyinga jack to the bumper, and any tendency toward roll, that is upwarddisplacement of the bumper relative to the vehicle body or the frame,during or incident to an impact. For this purpose, the base flange 52provides rigid guide and bearing surfaces closely cooperating with theupper and lower edges of the buckling column bar assembly 18. Suchbearing surfaces are conveniently provided by an upper edge 58 and alower edge 59 defining a clearance opening 60 (FIGS. 6 and 7) in theflange 52 and through which the bar assembly 18 extends. In addition,the flange 51 is provided with upper and lower co-extensive flanges 61and 62 (FIGS. 1, 5 and 6) which are spaced apart the same distance asthe space between the bearing edges 58 and 59 and thus provide rigidguiding and bearing surfaces freely closely cooperating with therespective upper and loweredges of the bar assembly 18 supplemental tothe surfaces 58 and 59. Through this arrangement excellent supportagainst vertical displacement of the bumper is attained. This functionis enhanced by having the edge bearing surfaces for the bar assembly 18as close as practicable to the outboard end of the bar assembly with aminimum outboard end portion of the buckling column bar assembly incantilever bumper supporting relation and the major extent of the barassembly 18 inboard between the flange 52 and the anchoring and abutmentbracket 35. Buckling deflections of the bar assembly 18 are readilyaccommodated by suitable width of the opening 60 in the direction whichthe bar assembly assumes during maximum bowing deflections.

In addition to their supplemental supporting function, the flanges 61and 62 function as bump stops having their outboard edges aligned withthe inboard edges of the bracket flanges 47 and spaced therefrom adistance predetermined to permit a full range of inboard displacement ofthe bumper relative to the supporting frame safely within the elasticlimits of buckling of the buckling column bars, and from there ontransferring inboard impact force to the vehicle frame through thebracket 51, 52.

In the modification of FIGS. 9-12, an arrangement is disclosed which isespecially suitable for smaller and lighterweight vehicles and wherein abumper 65 is supported on a vehicle frame 67 by means of an energyabsorbing buckling column bar system including, at each side of theframe a longitudinally extending resilient buckling column bar 68 and arelatively diagonally related buckling column bar 69. Attachment of theoutboard end of the bar 69 to the bumper 65 is through an inboardreinforcement 70 for the bumper carrying adjacent to its end an abutmentblock 71 to which the bar end is connected as by means of a bolt 72,with a rubber cushion 73 providing anti-rattle take-up and permittingpivoting or rocking of the bar end on the block. At its inboard end, thebar 69 is similarly connected to a longitudinally extending frame member74 which carries an abutment block 75 rigid on a mounting plate 77 whichis fixedly rigidly secured to the frame member 74 as by means of bolts78, means such as a bolt 79 and a rubber block 80 connecting the bar tothe block 75 for rocking pivotal movement of its bearing end in arattle-preventing manner.

In this instance, operative connection of the bar 68 to and between thebumper 65 and the supporting frame 67 is in a manner to permit energystoring buckling of the column 68 and the column 69 and to enablesupporting of the bumper by the buckling column bars 68 of the system,as well as to provide a feature of frictional energy absorptionsupplemental to the buckling columns on impact displacement of thebumper 65 toward the frame 67 and also energy absorption buffing onrebound return of the bumper by the buckling columns on release of thestored energy following impact. To this end, the inboard end of the bar68 is fixedly at tached to the frame member 74 in similar fashion as thebar 69 and on the same side but below and inboard from the abutment 75to accommodate a desirable length for the bar 68. Accordingly, there isrigidly carried by the inboard end portion of the mounting plate 77abutment means in the form of a block 81 against which the inboard endof the bar 68 thrusts in bearing relation and against which such endportion may be rigidly attached, but, as shown, is attached by means ofa bolt 82, with a rubber cushioning and rattle-preventing take-upcushion 83 interposed between the head of the bolt and the end portionof the bar.

In order to support the bumper 65 at a suitable elevation higher thanthe frame member 74, and to clear the abutment block 75, the inboardportion of the bar 68 is located at a suitably lower elevation than theoutboard portion of the bar, and with an offsetting uniform width ogeeconnection therebetween which will enable cooperative energy storingbuckling of all portions of the bar. Efficiency in the energy storingbuckling action of the bar 68, as well as the bar 69 is enhanced bysuitable configuration thereof, including generally lanceolate cut-outs85 in the opposite end portions of the bars extending longitudinallyfrom maximum outer end width toward narrowest dimension at their innerends, and also serving at their widest ends to accommodate bucklingdeflections of the associated end portions of the bars relative to theiranchoring bolts.

Fixed anchorage of the bar 68 at its outboard end to the bumper 65 maybe either rigidly or pivotally on the reinforcement 70. In thisinstance, mounting means in the form of a generally L-shaped flangebracket are provided including a base flange 87 attached by means ofarivet or bolt 88 to the reinforcement 70 and having an inwardlylongitudinally projecting flange 89 alongside the laterally inner faceof the bar 68, with a reinforcing rigid abutment member 90 providing anabutment thrust bearing seat for the outboard end of the bar. Attachmentof the bar 68 to the abutment 90 is by means comprising a bolt 91 and atake-up, anti-rattle resiliently yieldable rubber cushion 92 permittingpivotal or rocking movement of the attached end portion of the barduring energy storing buckling resulting from inboard displacement ofthe bumper 65 relative to the frame 67.

Means for holding the bumper 65 against vertical displacement relativeto the frame 67 and enabling utilizing the bumper for jacking lifting ofthe associated vehicle, comprise a rigid bracket 93 in the form of aplate rigidly secured as by means of bolts 94 to the frame member 74 andprojecting outboard therefrom parallel to the normal position of the bar68 and into lapping relation to the flange 89. For cooperation with thebar 68, the bracket 93 has means comprising rigid laterally outwardlyprojecting, preferably co-extensive upper and lower guide arms 95 whichhave opposed edges spaced apart to receive the respective upper andlower edges of the bar 68 in free slidable bearing relation permittingunobstructed buckling deflections of the bar but holding the bar againstvertical displacement. In addition, a cooperative relation between thebracket 93 and the bracket flange 89 is provided comprising meansenabling relative longitudinal movement but retaining these membersagainst vertical displacement. Conveniently such means comprise a pairof longitudinally spaced co-extensive pins 97 (FIGS. 11 and 12) in theform of bolts carried by the flange 89 and extending through alongitudinal slot 98 in the lapping portion of the plate member 93, theslot 98 being longitudinally elongated in the inboard direction toprovide ample clearance for full range of inboard displacement of thebumper 65 as enabled by the buckling column system. This arrangement isalso adapted for frictional energy absorption and buffing in cooperationwith the buckling column bars. For this purpose, the bolts 97 maintainfriction pad contact at the interface between the members 89 and 93sufficient to provide effective energy absorption and supplementaryforce damping during inboard stroke movement of the bumper, and returnstroke rebound buffing. In addition, by suitable length of the slot 98,its inboard end provides a bumper displacement limit stop 99 adapted tobe engaged by the inboardmost of the bolts 97. Thereby, energy storingbuckling of the bars 68 and 69 is controlled within safe elastic limitsand overstressing of the bars is avoided, and at the inboard limit ofbumper displacement, further impact force is transferred by the bracketplate 93 to the vehicle frame 67. If desired, a slightly prestressedcondition of the buckling column bar system may be attained by properlocation of the outboard end of the slot 98 providing a stop 100engageable by the outboardmost bolt 97 in the maximum outboard thrustnormal condition of the bumper support system, and wherein the bucklingcolumn bars 68 and 69 remain slightly biased under tension in thestarting direction toward which they are intended to buckle on impactagainst the bumper.

In FIG. 13 is shown an arrangement which is adapted for use in an energystoring bumper support system especially adapted for the heavier typesof so-called compact automobiles but not requiring the relativelygreater energy storing capacity ofa system such as that disclosed inrelation to the form of FIG. 1. Accordingly, a bumper is supportedimpact displaceably relative to a vehicle frame 107, with energy storingbuckling columns 108 and 109 connecting the bumper through inboardreinforcement 110 thereon with the frame. At its inboard end, the bar108 is fixedly connected to the laterally outer side ofa longitudinalframe member 111 by means of an abutment block 112 rigidly secured tothe frame member and providing a thrust seat for the inboard end of thebar relative to which such inboard end is maintained as by means of abolt 113 and a rattle-preventing take-up resilient rubber cushion 114.Inboard end mounting of the buckling column bar 109 is effected by meansof an abutment block 115 rigidly supported by a bracket plate 117attached as by means of bolts 118 to the frame member 111, a bolt 119attaching the bar to the block 115 with a rubber cushioning and take-upresilient block 120. At its outboard end the bar 109 may be secured tothe bumper in similar fashion as the outboard end of the bar 69 in FIG.9.

Outboard end attachment of the bar 108 to the bumper 105 may be rigidlyeffected, but is shown as pivotally fixed by means of a pin or bolt 121extending through a terminal thrust curl 122 provided on the end of thebar and received between a pair of co-extensive horizontal pinsupporting ear flanges 123 integral with a flange bracket having a baseflange 124 secured as by means of rivets or bolts 125 to thereinforcement 110 and provided with a longitudinally inboard extendingflange 127 from which the flange ears 123 extend. Reinforced support forthe ears 123 is provided by means comprising a flange member having abase flange 128 secured as by means of a rivet or bolt 129 to thereinforcement 110 and having longitudinally inboard extending flange 130edgewise between the ear flanges 123 and projecting co-extensive withthe flange 127. In this arrangement the flange 128 provides a bearingabutment for the outboard thrust terminal of the bar 108.

In addition to their buckling column bar supporting and anchoringfunction, the flanges 127 and 130 provide, together with an outboardextension 131 of the bracket plate 117 vertical displacement preventingmeans for the bumper 105 and energy absorbing friction pad and buffermeans. To this end, the bracket plate portion 131 is engaged infrictional face-to-face relation by and between the flanges 127 and 130,and connecting and clamping means comprising a pair of longitudinallyspaced bolts 132 are carried by flanges 127 and 130 and extend through aslot in the plate portion 131 on the order of the slot 98 in FIG. 12.Desirably spring washers 133 are provided in association with the boltsin order to assist in providing the desired frictional pressure againstthe plate portion 131 for effective inboard energy absorptionsupplemental to the energy storing function of the buckling column bars108 and 109 and outboard friction buffing during rebound. While thebolts 132 may provide substantial vertical displacement preventingsupport, a pair of coextensive laterally outwardly extending bearingarms 134 are desirably provided, on the order of the similar arms 95 inFIGS. 9 and 10, freely engageable in bearing relation with therespective upper and lower edges of the bar 108.

in any form of the invention, construction of the buckling column barsin such that in operation they will attain a high resistance level toendwise impact forces thereagainst initially and maintain thatresistance relatively constant throughout the available bumper supportsystem travel stroke. Namely, the bars will buckle resiliently withintheir elastic limits calculated to resist the full range of permissibledisplacement between the bumper and the frame and then, when the impactor other pressure is relieved, will return resiliently to normalposition, thereby returning the bumper to its normal position.Desirably, the buckling column bars are made from suitable springmaterial, such as SAE 1060 to 1080 steel heat-treated after formation ofthe bars to attain substantially bainite characteristics with a highdegree of toughness, strength and resilience. Typically, the bucklingcolumn bars may be of about )4; to 0.2 inch by 2 to 6 inchescross-section and with the effective lengths of the bars up to 36inches, depending upon the specific requirements of the particularbumper support system.

Because the respective opposite ends of the buckling column bars areanchored and all force transmission to the bars is through their endsand not crosswise to the bars, so that their length must shorten byresilient buckling upon impact of the bumper, they do not act the sameas springs to which the force is applied in the manner of a lever suchthat the action is relatively soft initially and then gradually buildsup to maximum resistance. Contrary to the action of a spring, thebuckling column bars resist deflection relatively constantly throughouttheir range of buckling resilience. Not only do the buckling column barsafford stable, substantially uniform resistance to impact force but theyalso return the bumper in the same uniform, stable manner after theimpact force or pressure terminates and the energy stored in thebuckling columns effects return thereof and thereby the bumper to theoriginal position.

It will be understood that variations and modifications may be effectedwithout departing from the spirit and scope of the novel concepts ofthis invention.

1 claim as my invention:

1. An energy storing system supporting a bumper inboard-displaceablyrelative to a supporting structure, comprising:

resilient buckling column bar means constructed of a non-elastomericmaterial having a relatively high modulus of elasticity, and arelatively high yield point, both in the order of heat-treated steel,and having a high force to short travel distance in the buckling modefixedly anchored inboard to the supporting structure and outboard to thebumper and operative in response to forced displacement of the bumperinboard relative to the supporting structure to buckle within a bucklingplane and store energy of the applied force; and

means carried rigidly by the supporting structure and including a partopposing said bar means in a plane generally parallel to said bucklingplane and permitting free buckling movements of the bar means in saidbuckling plane but holding the bar means against displacement from saidplane.

2. A system according to claim 1, including rigid abutment means carriedby the supporting structure, the bar means having inboard end bearingstructure thrusting against said abutment means and means connecting thebar means to said abutment means enabling pivoting of said end structureduring column buckling without interference with said thrusting of thebearing structure.

3. A system according to claim 1, including abutment means carried bythe bumper, said bar means having outboard end bearing structurethrusting against said abutment means, and means connecting the barmeans to said abutment means enabling pivotal movement of the bearingstructure during buckling of the bar means without interference withsaid thrusting of the bearing structure.

4. A system according to claim 3, said abutment means comprising abracket attached rigidly to the bumper, said bearing structurecomprising a curled bar terminal, and a pivot pin supported by saidbracket and engaged through said terminal curl.

5. A system according to claim 1, said means carried by the supportingstructure comprising a bracket having bearing means providing said partengageable with said bar means.

6. A system according to claim 5, said bearing means part comprisingopposed bearing flanges between which said bar means extend.

7. A system according to claim 5, said bearing means part comprising aflange having edges defining a clearance opening through said flange.

8. A system according to claim 1, said bumper comprising a vehiclebumper and said supporting structure comprising a vehicle frameincluding a longitudinal frame member having an outboard end relative towhich the bumper is supported in outboard spaced relation by said barmeans, said bar means comprising a resilient metal. bar having a lengthextending from an outboard end anchored to the bumper to an inboard endanchored to said frame member a substantial distance inboard from saidoutboard end of the frame member and with the major extent of the barextending along said frame member, said bar having a width stronglyresisting load deflections and oriented vertically and a thicknessfacilitating resilient buckling in horizontal direction responsive toendwise force applied longitudinally to the bar, said means carried bythe supporting structure being mounted adjacent to said outboard end ofthe frame member providing rigid restraint against verticaldisplacements of the bar from dead load of bumper and bar and jackingloads when the vehicle is raised by a jack applied under the bumper butpermitting said free buckling movements in horizontal direction relativeto the frame member.

9. A system according to claim 1, including a stop flange carried by thebumper, and a stop flange carried by the supporting structure, said stopflange being normally spaced apart a predetermined bumper displacementstroke distance and being engageable at the stroke limit to transferforce from the bumper to the supporting structure.

10. An energy storing system supporting a bumper inboard displaceablyrelative to a supporting structure, comprising:

resilient buckling column bar means fixedly anchored inboard to thesupporting structure and outboard to the bumper and operative inresponse to forced displacement of the bumper inboard relative to thesupporting structure to buckle within a buckling plane and store energyof the applied force;

means carried by the supporting structure permitting free bucklingmovements of the bar means in said buckling plane but holding the barmeans against displacement from said plane; abutment means carried bythe bumper against which outboard end bearing structure of the bar meansthrust, and means connecting the bar means to said abutment meansenabling pivotal movement of the bearing structure during buckling ofthe bar means;

said abutment means comprising a bracket attached rigidly to the bumper;

said bearing structure comprising a curled bar terminal; and

a pivot pin supported by said bracket and engaged through said terminalcurl.

11. A system according to claim 10, said bar means comprising aplurality of bars in laminar relation, and means securing the barstogether adjacent to said curl.

12. An energy storing system supporting a bumper inboard-displaceablyrelative to a supporting structure, comprising:

resilient buckling column bar means fixedly anchored inboard to thesupporting structure and outboard to the bumper and operative inresponse to forced displacement of the bumper inboard relative to thesupporting structure to buckle within a buckling plane and store energyof the applied force;

mean carried by the supporting structure permitting free bucklingmovements of the bar means in said buckling plane but holding the barmeans against displacement from said plane;

bracket structure carried by the bumper and providing means for fixedlyanchoring the bar means to the bumper;

means carried by said bracket structure and by said means carried by thesupporting structure cooperatively providing energy absorbing frictionpad means operative supplemental to the energy storing operation of thebar means during inboard forced displacement of the bumper relative tothe supporting structure;

said friction pad means comprising respective flanges in face-to-facefrictional engagement; and

means pressing the flanges together in relatively frictionally slidablerelation.

13. A system according to claim 12, one of said flanges having alongitudinal slot, said means pressing the flanges together comprising apair of longitudinally spaced bolts carried by the other of said flangesand as sisting said means carried by the supporting structure in holdingthe bar means in said buckling plane.

14. An energy storing system supporting a bumper inboard-displaceablyrelative to a supporting structure, comprising:

resilient buckling column bar means fixedly anchored inboard to thesupporting structure and outboard to the bumper and operative inresponse to forced displacement of the bumper inboard relative to thesupporting structure to buckle within a buckling plane and store energyof the applied force; and

means carried by the supporting structure permitting free bucklingmovements of the bar means in said buckling plane but holding the barmeans against displacement from said plane;

said bumper comprising a vehicle bumper and said supporting structurecomprising a vehicle frame including a longitudinal frame member havingan outboard end relative to which the bumper is supported in outboardspaced relation by said bar means;

said bar means comprising a resilient metal bar having a lengthextending from an outboard end anchored to the bumper to an inboard endanchored to said frame member a substantial distance inboard from saidoutboard end of the frame member and with the major extent of the barextending along said frame member;

said bar having a width strongly resisting load deflections and orientedvertically and a thickness facilitating resilient buckling in horizontaldirection responsive to endwise force applied longitudinally to the bar;

said means carried by the supporting structure being mounted adjacent tosaid outboard end of the frame member providing rigid restraint againstvertical displacements of the bar from dead load of bumper and bar andjacking loads when the vehicle is raised by a jack applied under thebumper but permitting said free buckling movements in horizontaldirection relative to the frame member.

15. A system according to claim 14, said bar being mounted above saidframe member and said buckling movements being over the top of saidframe member.

16. A system according to claim 14, said bar being mounted along a sideof said frame member and said buckling movements being in a directionaway from said side of the frame member.

17. A system according to claim 14, said bar being mounted operativelyabove said frame member, and a second resilient buckling column barextending diagonally to and between and having its respective oppositeends anchored to a side of said frame member and to said bumper.

18. A system according to claim 14, including a second resilientbuckling column bar extending diagonally between and having its oppositeends respectively anchored to said bumper and extending therefrom towardone side of the frame member and anchored to the frame member at anelevation adjacent to the top of the frame member, and saidfirst-mentioned resilient buckling column bar extending along the sameside of the frame member below said diagonal bar and having anoffsetting intermediate portion placing the outboard end portion of saidfirst-mentioned bar at substantially the same elevation as the outboardend of the diagonal bar.

19. A system according to claim 18, comprising a mounting plate securedto said one side of the frame member, and the inboard ends of said barsbeing anchored to the plate and thereby to said frame member.

20. A system according to claim 19, including a second plate membersecured to the same side of said frame member and providing said meanscarried by the supporting structure.

21. A system according to claim 18, including a mounting plate securedto said frame member and providing the anchorage for said diagonal bar,said mounting plate also providing said means carried by the supportingstructure.

22. A system according to claim 21, said plate having a flange portionprojecting outboard, a friction pad flange extending inboard from saidbumper in lapping relation to said flange extension, and means pressingsaid flange and flange extension together in frictional sliding energyabsorbing relation.

t i k

1. An energy storing system supporting a bumper inboarddisplaceablyrelative to a supporting structure, comprising: resilient bucklingcolumn bar means constructed of a nonelastomeric material having arelatively high modulus of elasticity, and a relatively high yieldpoint, both in the order of heat-treated steel, and having a high forceto short travel distance in the buckling mode fixedly anchored inboardto the supporting structure and outboard to the bumper and operative inresponse to forced displacement of the bumper inboard relative to thesupporting structure to buckle within a buckling plane and store energyof the applied force; and means carried rigidly by the supportingstructure and including a part opposing said bar means in a planegenerally parallel to said buckling plane and permitting free bucklingmovements of the bar means in said buckling plane but holding the barmeans against displacement from said plane.
 2. A system according toclaim 1, including rigid abutment means carried by the supportingstructure, the bar means having inboard end bearing structure thrustingagainst said abutment means and mEans connecting the bar means to saidabutment means enabling pivoting of said end structure during columnbuckling without interference with said thrusting of the bearingstructure.
 3. A system according to claim 1, including abutment meanscarried by the bumper, said bar means having outboard end bearingstructure thrusting against said abutment means, and means connectingthe bar means to said abutment means enabling pivotal movement of thebearing structure during buckling of the bar means without interferencewith said thrusting of the bearing structure.
 4. A system according toclaim 3, said abutment means comprising a bracket attached rigidly tothe bumper, said bearing structure comprising a curled bar terminal, anda pivot pin supported by said bracket and engaged through said terminalcurl.
 5. A system according to claim 1, said means carried by thesupporting structure comprising a bracket having bearing means providingsaid part engageable with said bar means.
 6. A system according to claim5, said bearing means part comprising opposed bearing flanges betweenwhich said bar means extend.
 7. A system according to claim 5, saidbearing means part comprising a flange having edges defining a clearanceopening through said flange.
 8. A system according to claim 1, saidbumper comprising a vehicle bumper and said supporting structurecomprising a vehicle frame including a longitudinal frame member havingan outboard end relative to which the bumper is supported in outboardspaced relation by said bar means, said bar means comprising a resilientmetal bar having a length extending from an outboard end anchored to thebumper to an inboard end anchored to said frame member a substantialdistance inboard from said outboard end of the frame member and with themajor extent of the bar extending along said frame member, said barhaving a width strongly resisting load deflections and orientedvertically and a thickness facilitating resilient buckling in horizontaldirection responsive to endwise force applied longitudinally to the bar,said means carried by the supporting structure being mounted adjacent tosaid outboard end of the frame member providing rigid restraint againstvertical displacements of the bar from dead load of bumper and bar andjacking loads when the vehicle is raised by a jack applied under thebumper but permitting said free buckling movements in horizontaldirection relative to the frame member.
 9. A system according to claim1, including a stop flange carried by the bumper, and a stop flangecarried by the supporting structure, said stop flange being normallyspaced apart a predetermined bumper displacement stroke distance andbeing engageable at the stroke limit to transfer force from the bumperto the supporting structure.
 10. An energy storing system supporting abumper inboard displaceably relative to a supporting structure,comprising: resilient buckling column bar means fixedly anchored inboardto the supporting structure and outboard to the bumper and operative inresponse to forced displacement of the bumper inboard relative to thesupporting structure to buckle within a buckling plane and store energyof the applied force; means carried by the supporting structurepermitting free buckling movements of the bar means in said bucklingplane but holding the bar means against displacement from said plane;abutment means carried by the bumper against which outboard end bearingstructure of the bar means thrust, and means connecting the bar means tosaid abutment means enabling pivotal movement of the bearing structureduring buckling of the bar means; said abutment means comprising abracket attached rigidly to the bumper; said bearing structurecomprising a curled bar terminal; and a pivot pin supported by saidbracket and engaged through said terminal curl.
 11. A system accordingto claim 10, said bar means comprising a plurality of bars in laminarrelation, and means securing the bars togeTher adjacent to said curl.12. An energy storing system supporting a bumper inboard-displaceablyrelative to a supporting structure, comprising: resilient bucklingcolumn bar means fixedly anchored inboard to the supporting structureand outboard to the bumper and operative in response to forceddisplacement of the bumper inboard relative to the supporting structureto buckle within a buckling plane and store energy of the applied force;mean carried by the supporting structure permitting free bucklingmovements of the bar means in said buckling plane but holding the barmeans against displacement from said plane; bracket structure carried bythe bumper and providing means for fixedly anchoring the bar means tothe bumper; means carried by said bracket structure and by said meanscarried by the supporting structure cooperatively providing energyabsorbing friction pad means operative supplemental to the energystoring operation of the bar means during inboard forced displacement ofthe bumper relative to the supporting structure; said friction pad meanscomprising respective flanges in face-to-face frictional engagement; andmeans pressing the flanges together in relatively frictionally slidablerelation.
 13. A system according to claim 12, one of said flanges havinga longitudinal slot, said means pressing the flanges together comprisinga pair of longitudinally spaced bolts carried by the other of saidflanges and assisting said means carried by the supporting structure inholding the bar means in said buckling plane.
 14. An energy storingsystem supporting a bumper inboard-displaceably relative to a supportingstructure, comprising: resilient buckling column bar means fixedlyanchored inboard to the supporting structure and outboard to the bumperand operative in response to forced displacement of the bumper inboardrelative to the supporting structure to buckle within a buckling planeand store energy of the applied force; and means carried by thesupporting structure permitting free buckling movements of the bar meansin said buckling plane but holding the bar means against displacementfrom said plane; said bumper comprising a vehicle bumper and saidsupporting structure comprising a vehicle frame including a longitudinalframe member having an outboard end relative to which the bumper issupported in outboard spaced relation by said bar means; said bar meanscomprising a resilient metal bar having a length extending from anoutboard end anchored to the bumper to an inboard end anchored to saidframe member a substantial distance inboard from said outboard end ofthe frame member and with the major extent of the bar extending alongsaid frame member; said bar having a width strongly resisting loaddeflections and oriented vertically and a thickness facilitatingresilient buckling in horizontal direction responsive to endwise forceapplied longitudinally to the bar; said means carried by the supportingstructure being mounted adjacent to said outboard end of the framemember providing rigid restraint against vertical displacements of thebar from dead load of bumper and bar and jacking loads when the vehicleis raised by a jack applied under the bumper but permitting said freebuckling movements in horizontal direction relative to the frame member.15. A system according to claim 14, said bar being mounted above saidframe member and said buckling movements being over the top of saidframe member.
 16. A system according to claim 14, said bar being mountedalong a side of said frame member and said buckling movements being in adirection away from said side of the frame member.
 17. A systemaccording to claim 14, said bar being mounted operatively above saidframe member, and a second resilient buckling column bar extendingdiagonally to and between and having its respective opposite endsanchored to a side of said frame member and to said bumper.
 18. A systemaccording to claim 14, includiNg a second resilient buckling column barextending diagonally between and having its opposite ends respectivelyanchored to said bumper and extending therefrom toward one side of theframe member and anchored to the frame member at an elevation adjacentto the top of the frame member, and said first-mentioned resilientbuckling column bar extending along the same side of the frame memberbelow said diagonal bar and having an offsetting intermediate portionplacing the outboard end portion of said first-mentioned bar atsubstantially the same elevation as the outboard end of the diagonalbar.
 19. A system according to claim 18, comprising a mounting platesecured to said one side of the frame member, and the inboard ends ofsaid bars being anchored to the plate and thereby to said frame member.20. A system according to claim 19, including a second plate membersecured to the same side of said frame member and providing said meanscarried by the supporting structure.
 21. A system according to claim 18,including a mounting plate secured to said frame member and providingthe anchorage for said diagonal bar, said mounting plate also providingsaid means carried by the supporting structure.
 22. A system accordingto claim 21, said plate having a flange portion projecting outboard, afriction pad flange extending inboard from said bumper in lappingrelation to said flange extension, and means pressing said flange andflange extension together in frictional sliding energy absorbingrelation.